MM58242

MM58242 High Voltage Display Driver March 1991 MM58242 High Voltage Display Driver General Description The MM58242 is a monolithic MOS integrated circuit utilizing CMOS metal gate low threshold P and N-channel devices It is available both in 28-pin molded dual-in-line packages or as dice The MM58242 is particularly suited for driving high voltage (60V max) vacuum fluorescent (VF) displays (e g a 20-digit alphanumeric or dot matrix display) Features Y Y Y Y Y Y Y Y Y Applications Y Y Y Y Y Y COPSTM or microprocessor-driven displays Instrumentation readouts Industrial control indicator Digital clock thermostat counter voltmeter Word processor text displays Automotive dashboards Direct interface to high voltage display Serial data input No external resistors required Wide display power supply operation LSTTL compatible inputs Software compatible with NS display driver family Compatible with alphanumeric or dot matrix displays Display blanking control input Simple to cascade Block Diagram TL F 7924 – 1 FIGURE 1 COPSTM is a trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL F 7924 RRD-B30M105 Printed in U S A Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Voltage at Any Input Pin Voltage at Any Display Pin VDD a lVDISl Storage Temperature Power Dissipation at a 25 C Molded DIP Package Board Mount Molded DIP Package Socket Mount Junction Temperature VDD a 0 3V to VSS b0 3V VDD to VDD b62 5V 62 5V b 65 C to a 150 C 2 03W 1 83W 130 C Operating Conditions Min Supply Voltage (VDD) VSS e 0V Display Voltage (VDIS) Temperature Range 45 b 55 b 40 Max 55 b 25 a 85 Units V V C Lead Temperature (Soldering 10 sec ) 260 C Molded DIP Package Board Mount iJA e 52 C W Derate 19 2 mW C above a 25 C Molded DIP Package Socket Mount iJA e 58 C W Derate 17 2 mW C above a 25 C DC Electrical Characteristics TA e b40 C to a 85 C VDD e 5V g 0 5V VSS e 0V unless otherwise specified Symbol IDD IDIS Parameter Power Supply Currents Conditions VIN e VSS or VDD VSS e 0V VDIS Disconnected VDD e 5 5V VSS e 0V VDIS e 55V All Outputs Low Min Typ Max 150 10 Units mA mA VIL VIH VOL VOH VOH IIN Input Logic Levels DATA IN CLOCK ENABLE BLANK Logic ‘0’ Logic ‘1’ Data Output Logic Levels Logic ‘0’ Logic ‘1’ Logic ‘1’ Input Currents DATA IN CLOCK ENABLE BLANK Input Capacitance DATA IN CLOCK ENABLE BLANK Display Output Impedances Output Off (Figure 3a) 08 (Note 1) IOUT e 400 mA IOUT e b10 mA IOUT e b500 mA VIN e 0V or VDD 24 04 VDDb0 5 28 b 10 V V V V V mA 10 CIN 15 pF ROFF RON Output On (Figure 3b) VDD e 5 5V VSS e 0V VDIS e b25V VDIS e b40V VDIS e b55V VDIS e b25V VDIS e 40V VDIS e b55V VDD e 5 5V IOUT e Open Circuit b 55V s VDIS s b 25V IOUT e b 400 mA 60 70 80 30 26 23 VDIS 400 550 650 40 37 34 VDIS a 4 kX kX kX kX kX kX V VDOL Display Output Low Voltage Note 1 74LSTTL VOH e 2 7V IOUT e b 400 mA TTL VOH e 2 4V 2 AC Electrical Characteristics TA e b40 C to a 85 C Parameter Clock Input Frequency fC High Time tH Low Time tL Data Input Set-Up Time tDS Hold Time tDH Enable Input Set-Up Time tES Hold Time tEH Data Output CLOCK Low to Data Out Time tCDO (Note 2) 100 100 CL e 50 pF Conditions (Notes 3 and 4) Min VDD e 5V g 0 5V Typ Max 800 Units kHz ns ns ns ns ns ns 500 ns 300 300 100 100 Note 2 For timimg purposes the signals ENABLE and BLANK can be considered to be totally independent of each other Note 3 AC input waveform specification for test purposes tr s 20 ns tf s 20 ns f e 800 kHz 50% g 10% duty cycle Note 4 Clock input rise and fall times must not exceed 5 ms Connection Diagrams Dual-In-Line Package Plastic Chip Carrier TL F 7924 – 8 TL F 7924 – 2 Top View Order Number MM58242V See NS Package Number V28A Top View FIGURE 2 Order Number MM58242N See NS Package Number N28B 3 Functional Description This product is specifically designed to drive multiplexed or non-multiplexed high voltage alphanumeric or dot matrix vacuum fluorescent (VF) displays Character generation is done externally in the microprocessor with a serial data path to the display driver The MM58242 uses three signals DATA IN CLOCK and ENABLE where ENABLE acts as an external load signal Display blanking can be achieved by means of the BLANKING CONTROL input and a logic ‘1’ will turn off all sections of the display A block diagram of the MM58242 is shown in Figure 1 Figure 2 shows the pinout of the MM58242 device where output 1 (pin 12) is equivalent to bit 1 (i e the first bit of data to be loaded into the shift register following ENABLE high) A logic ‘1’ at the input will turn on the corresponding display digit segment dot output A significant reduction in discrete board components can be achieved by use of the MM58242 because external pulldown resistors are not required Due to the nature of the output stage both its on and off impedance values vary as a function of the display voltage applied However Figures 3a and 3b show that this output impedance will remain constant for a fixed value of display voltage To clear (reset) the display driver at ‘‘power on’’ or any time the following flushing routine may be used With the enable signal high clock in 20 zeroes Drive the enable signal low and the display will be blank It is recommended to clear the driver at power on In Figure 5 the ENABLE signal acts as an envelope and only while this signal is at a logic ‘1’ does the circuit accept CLOCK input signals Data is transferred and shifted in the internal shift register on the rising clock edge i e ‘0’ – ‘1’ transition When the ENABLE signal goes low the contents of the shift registers are latched and the display will show new data During data transfer the display will show old data DATA OUT is also provided on the MM58242 being output on the falling edge At any time the display may be blanked under processor control using the BLANKING CONTROL input Figure 4 demonstrates the critical timing requirements between CLOCK and DATA IN for the MM58242 Figure 6 shows a schematic diagram of a microprocessorbased system where the MM58242 is used to provide the grid drive for a 40-digit 2 line 5 c 7 multiplexed vacuum fluorescent (VF) display The anode drive in this example is provided by another member of the high voltage display driver family namely the MM58248 which does not require an externally generated load signal TL F 7924 – 3 FIGURE 3a Output Impedance Off TL F 7924 – 4 FIGURE 3b Output Impedance On 4 Timing Diagrams TL F 7924 – 5 For the purposes of AC measurement VIH e 2 4V VIL e 0 8V FIGURE 4 Clock and Data Timings TL F 7924 – 6 FIGURE 5 MM58242 Timings (Data Format) Typical Application TL F 7924 – 7 FIGURE 6 Microprocessor-Controlled Word Processor 5 MM58242 High Voltage Display Driver Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number MM58242N NS Package Number N28B LIFE SUPPORT POLICY Plastic Chip Carrier (V) Order Number MM58242V NS Package Number V28A NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or systems which (a) are intended for surgical implant into the body or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user National Semiconductor Corporation 1111 West Bardin Road Arlington TX 76017 Tel 1(800) 272-9959 Fax 1(800) 737-7018 2 A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor Europe Fax (a49) 0-180-530 85 86 Email cnjwge tevm2 nsc com Deutsch Tel (a49) 0-180-530 85 85 English Tel (a49) 0-180-532 78 32 Fran ais Tel (a49) 0-180-532 93 58 Italiano Tel (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd 13th Floor Straight Block Ocean Centre 5 Canton Rd Tsimshatsui Kowloon Hong Kong Tel (852) 2737-1600 Fax (852) 2736-9960 National Semiconductor Japan Ltd Tel 81-043-299-2309 Fax 81-043-299-2408 National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications